An apparatus as defined above is disclosed in EP 0 417 728 A2. The known apparatus, e.g. a television receiver or a video recorder, comprises a user-operable control circuit for generating a sequence of commands which cause a number of functions of the apparatus to be invoked consecutively. Examples of functions invoked by the control circuit are picture-in-picture, zoom-effect, mosaic screen and features for enhancing the picture quality, such as noise filters, cross-color and interference reduction. The effects of the functions invoked by the control circuit are observable on the television screen, giving a potential buyer of the apparatus an impression of its functions.
A disadvantage of the known apparatus is that the effectiveness of the demonstration of said functions heavily depends on the video contents being received at the time of demonstration.